Add code to cleanup PangoLayout objects when done with them

[acre] / acre.c

diff --git a/acre.c b/acre.c
index 6149cd38515b849786643811547351970393bb5a..1b238fdb33babc5471f818e886b9b708ca9790f0 100644 (file)
--- a/acre.c
+++ b/acre.c
@@ -19,6 +19,7 @@
 
 #define _ISOC99_SOURCE /* for round() */
 #define _XOPEN_SOURCE 500
+#define _GNU_SOURCE /* for asprintf() */
 
 #include "acre.h"
 #include "xmalloc.h"
@@ -56,6 +57,7 @@ struct _acre {
 
     /* Data for drawing. */
     cairo_t *cr;
+    PangoFontDescription *font;
 
     /* Total size including labels. */
     int width;
@@ -156,11 +158,38 @@ acre_add_data (acre_t *acre, acre_data_t *data)
 #define ACRE_PAD (ACRE_FONT_SIZE)
 #define ACRE_TICK_SIZE 6
 
+static PangoLayout *
+_create_layout (acre_t *acre, const char *text)
+{
+    PangoLayout *layout;
+
+    layout = pango_cairo_create_layout (acre->cr);
+    pango_layout_set_font_description (layout, acre->font);
+    pango_layout_set_text (layout, text, -1);
+    pango_layout_set_alignment (layout, PANGO_ALIGN_CENTER);
+
+    return layout;
+}
+
+static void
+_destroy_layout (PangoLayout *layout)
+{
+    g_object_unref (layout);
+}
+
+static void
+_show_layout (cairo_t *cr, PangoLayout *layout)
+{
+    pango_cairo_show_layout (cr, layout);
+
+    _destroy_layout (layout);
+}
+
 static void
 _draw_title_and_labels (acre_t *acre)
 {
     cairo_t *cr = acre->cr;
-    PangoFontDescription *acre_font, *title_font;
+    PangoFontDescription *title_font;
     PangoLayout *title_layout, *x_axis_layout, *y_axis_layout;
     int title_width, title_height;
     int x_axis_width, x_axis_height;
@@ -169,9 +198,9 @@ _draw_title_and_labels (acre_t *acre)
 
     cairo_save (cr);
 
-    acre_font = pango_font_description_new ();
-    pango_font_description_set_family (acre_font, ACRE_FONT_FAMILY);
-    pango_font_description_set_absolute_size (acre_font,
+    acre->font = pango_font_description_new ();
+    pango_font_description_set_family (acre->font, ACRE_FONT_FAMILY);
+    pango_font_description_set_absolute_size (acre->font,
                                              ACRE_FONT_SIZE * PANGO_SCALE);
 
     title_font = pango_font_description_new ();
@@ -179,20 +208,11 @@ _draw_title_and_labels (acre_t *acre)
     pango_font_description_set_absolute_size (title_font,
                                              ACRE_TITLE_FONT_SIZE * PANGO_SCALE);
 
-    title_layout = pango_cairo_create_layout (cr);
+    title_layout = _create_layout (acre, acre->title);
     pango_layout_set_font_description (title_layout, title_font);
-    pango_layout_set_text (title_layout, acre->title, -1);
-    pango_layout_set_alignment (title_layout, PANGO_ALIGN_CENTER);
-
-    x_axis_layout = pango_cairo_create_layout (cr);
-    pango_layout_set_font_description (x_axis_layout, acre_font);
-    pango_layout_set_text (x_axis_layout, acre->x_axis.label, -1);
-    pango_layout_set_alignment (x_axis_layout, PANGO_ALIGN_CENTER);
 
-    y_axis_layout = pango_cairo_create_layout (cr);
-    pango_layout_set_font_description (y_axis_layout, acre_font);
-    pango_layout_set_text (y_axis_layout, acre->y_axis.label, -1);
-    pango_layout_set_alignment (y_axis_layout, PANGO_ALIGN_CENTER);
+    x_axis_layout = _create_layout (acre, acre->x_axis.label);
+    y_axis_layout = _create_layout (acre, acre->y_axis.label);
 
     /* Iterate with the layout of the title and axis labels until they
      * are stable, (this requires iteration since we don't know what
@@ -235,21 +255,21 @@ _draw_title_and_labels (acre_t *acre)
     cairo_set_source_rgb (cr, 0, 0, 0);
 
     cairo_move_to (cr, acre->chart.x, ACRE_PAD);
-    pango_cairo_show_layout (cr, title_layout);
+    _show_layout (cr, title_layout);
 
     cairo_save (cr);
     {
        cairo_translate (cr, ACRE_PAD, acre->chart.y + acre->chart.height);
        cairo_rotate (cr, - M_PI / 2.0);
        cairo_move_to (cr, 0, 0);
-       pango_cairo_show_layout (cr, y_axis_layout);
+       _show_layout (cr, y_axis_layout);
     }
     cairo_restore (cr);
 
     cairo_move_to (cr, acre->chart.x,
                   acre->chart.y + acre->chart.height +
                   ACRE_FONT_SIZE + ACRE_PAD);
-    pango_cairo_show_layout (cr, x_axis_layout);
+    _show_layout (cr, x_axis_layout);
 
     cairo_restore (cr);
 }
@@ -442,11 +462,33 @@ _draw_frame_and_ticks (acre_t *acre)
            cairo_move_to (cr, x, acre->y_axis.min);
            cairo_save (cr);
            {
-               cairo_identity_matrix (cr);
-               cairo_rel_line_to (cr, 0, 0.5);
-               cairo_rel_line_to (cr, 0, -ACRE_TICK_SIZE-0.5);
-               cairo_set_line_width (cr, 1.0);
-               cairo_stroke (cr);
+               /* tick */
+               cairo_save (cr);
+               {
+                   cairo_identity_matrix (cr);
+                   cairo_rel_line_to (cr, 0, 0.5);
+                   cairo_rel_line_to (cr, 0, -ACRE_TICK_SIZE-0.5);
+                   cairo_set_line_width (cr, 1.0);
+                   cairo_stroke (cr);
+               }
+               cairo_restore (cr);
+
+               /* label */
+               cairo_save (cr);
+               {
+                   PangoLayout *layout;
+                   char *label;
+                   int width, height;
+                   asprintf (&label, "%g", x);
+                   layout = _create_layout (acre, label);
+                   free (label);
+                   cairo_move_to (cr, x, acre->y_axis.min);
+                   cairo_identity_matrix (cr);
+                   pango_layout_get_pixel_size (layout, &width, &height);
+                   cairo_rel_move_to (cr, -width / 2, 2);
+                   _show_layout (cr, layout);
+               }
+               cairo_restore (cr);
            }
            cairo_restore (cr);
            x += step;
@@ -458,11 +500,33 @@ _draw_frame_and_ticks (acre_t *acre)
            cairo_move_to (cr, acre->x_axis.min, y);
            cairo_save (cr);
            {
-               cairo_identity_matrix (cr);
-               cairo_rel_line_to (cr, -0.5, 0);
-               cairo_rel_line_to (cr, ACRE_TICK_SIZE+0.5, 0);
-               cairo_set_line_width (cr, 1.0);
-               cairo_stroke (cr);
+               /* tick */
+               cairo_save (cr);
+               {
+                   cairo_identity_matrix (cr);
+                   cairo_rel_line_to (cr, -0.5, 0);
+                   cairo_rel_line_to (cr, ACRE_TICK_SIZE+0.5, 0);
+                   cairo_set_line_width (cr, 1.0);
+                   cairo_stroke (cr);
+               }
+               cairo_restore (cr);
+
+               /* label */
+               cairo_save (cr);
+               {
+                   PangoLayout *layout;
+                   char *label;
+                   int width, height;
+                   asprintf (&label, "%g", y);
+                   layout = _create_layout (acre, label);
+                   free (label);
+                   cairo_move_to (cr, acre->x_axis.min, y);
+                   cairo_identity_matrix (cr);
+                   pango_layout_get_pixel_size (layout, &width, &height);
+                   cairo_rel_move_to (cr, -width-2, -height/2);
+                   _show_layout (cr, layout);
+               }
+               cairo_restore (cr);
            }
            cairo_restore (cr);
            y += step;